Linux advocates have for so long advocated browser-accessed software as a service as a way to break out of Microsoft's proprietary desktop. Now that this world has arrived, there's less incentive to work on native Linux apps.

If you would like users to switch to Linux then you _should_ support the idea of Linux-only software. There's a catch however.

If he supports Linux-only apps there is no catch, at least not the catch you mention.

Linux has tons of mediocre-to-crap but very little "great" software.

So it's just like Windows, only with much less crap and mediocre software. One look at, say, Tucows confirms this without a doubt. There are great Linux software, there are great Windows software and great OSX software etc. Perhaps Linux has less, perhaps not. The only "great" software Windows has that I need are games. There's not one other piece of software Windows has that I need. That's just me though, it will be different for everyone and depend greatly what you do with your computer.